A track loader is an engineering vehicle

Engineering vehicle

Heavy equipment refers to heavy-duty vehicles, specially designed for executing construction tasks, most frequently ones involving earthwork operations. They are also known as, construction equipment, construction plant, earth movers, engineering vehicles, or simply equipment...

 consisting of a tracked chassis

Chassis

A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...

 with a loader

Loader (equipment)

A loader is a heavy equipment machine often used in construction, primarily used to load material into or onto another type of machinery .-Heavy equipment front loaders:A loader A loader is a heavy equipment machine often used in construction, primarily used to load material (such as asphalt,...

 for digging and loading material. The history of track loaders can be defined by three evolutions of their design. Each of these evolutions made the track loader a more viable and versatile tool in the excavation industry. These machines are capable in nearly every task, but master of none. A dozer, excavator, or wheel loader will out perform a track loader under a set of conditions, but the ability of a track loader perform almost every task on a job site is why it remains a part of many companies' fleets.

The first track loaders were built from track tractor

Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

s with scratch built loaders. The first loaders were cable operated like the bulldozers of the era. These track loaders lacked the ability to dig in hard ground, but so did the dozers of the day. They were mostly used for moving stockpiled material and loading trucks and rail cars.

The first major design change to track loaders came with the integration of hydraulic

Hydraulics

Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...

 systems. Using hydraulics to power the loader linkages increased the power of the loader. More importantly, the loaders could apply downpressure to the bucket, vastly increasing their ability to dig unworked ground. Most of the track loaders were still based on a bulldozer

Bulldozer

A bulldozer is a crawler equipped with a substantial metal plate used to push large quantities of soil, sand, rubble, etc., during construction work and typically equipped at the rear with a claw-like device to loosen densely-compacted materials.Bulldozers can be found on a wide range of sites,...

 equivalent. The weight of the engine was still on the front half of the tracks along with the heavy loader components. This caused many problems with heavy wear of the front idler wheels and the undercarriage in general. The Caterpillar 983 track loader, the second largest track loader ever built, was notorious for heavy undercarriage wear.

The hydrostatic drive system was the second major innovation to affect the design of track loaders.

Track loaders have become very sophisticated machines, using hydrostatic transmissions

Transmission (mechanics)

A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...

 and electro-hydraulic controls to increase efficiency. Until the rise in popularity of excavator

Excavator

Excavators are heavy construction equipment consisting of a boom, stick, bucket and cab on a rotating platform . The house sits atop an undercarriage with tracks or wheels. A cable-operated excavator uses winches and steel ropes to accomplish the movements. They are a natural progression from the...

s, track loaders had little competition digging and loading jobs.